Grafting of nitroxyl terminated oligomers or polymers onto thermoplastic polymers

ABSTRACT

The instant invention relates to a process for the preparation of grafted polymers wherein in a first step A) a oligomer or polymer is prepared by controlled radical polymerization in the presence of a stable free nitroxyl radical or a nitroxylether to obtain a nitroxyl terminated oligomer or polymer and in a second step B) the nitroxyl terminated oligomer or polymer is mixed and reacted with a thermoplastic or elastomeric polymer or copolymer in its molten state at a temperature at which cleavage of the nitroxyl-polymer/oligomer bond occurs, whereby the nitroxyl terminated oligomer or polymer is grafted onto the thermoplastic or elastomeric polymer. A further subject of the present invention is a grafted polymer prepared by said process.

The instant invention relates to a process for the preparation ofgrafted (co)polymers wherein in a first step A) an oligomer or polymeris prepared by controlled free radical polymerization in the presence ofa stable free nitroxyl radical or a nitroxylether to obtain a nitroxylterminated oligomer or polymer and in a second step B) the nitroxylterminated oligomer or polymer is mixed and reacted with a thermoplasticor elastomeric polymer or copolymer at a temperature at which cleavageof the nitroxyl-polymer/oligomer bond occurs, whereby the nitroxylterminated oligomer or polymer is chemically bonded to the thermoplasticor elastomeric polymer. A further aspect of the present invention is agrafted/comb (co)polymer prepared by said process.

Increasing activities have been directed towards chemical modificationsof existing polymers in order to obtain functional and/or engineered newmaterials. Chemical modifications of existing polymers are important forat least two reasons: 1. They can be an inexpensive and rapid way ofobtaining new polymers without having to search for new monomers; 2.they may be the only way to synthesize polymers with the intended newcharacteristics.

An important chemical modification is the free radical grafting offunctionalized or reactive monomers, which involves reaction of apolymer with a vinyl-group containing monomer or mixture of monomerscapable of forming grafts onto the polymer backbone. By selectingmonomers, length of the grafts, number of grafts adjustment of polymerproperties is feasible. For example, if the grafts are long enough orthe quantity of grafts is high, the modified polymer has properties of atrue graft copolymer, which will be different from those of the originalpolymer substrate and combines usually properties of the parentpolymers. When the grafts are short with less than, for example fivemoieties or the quantity of the grafts is low, most of the physical andor mechanical properties of the modified polymer substrate will beretained. Nevertheless, these changes can e.g. result in alteredadhesion and surface properties or modified compatibilization behaviorwith other substrates. However, technically it is very difficult totailor the different parameters of monomer structure, number of graftsand molecular weight of grafted chains.

The advantages of free radical-grafting are further gained with the useof batch mixers or screw extruders as chemical reactors, which allow thefree radical-grafting reaction to occur without solvents. This is forexample described by G. H. Hu et al., in “Reactive Modifiers forPolymers”, first edition, Blackie Academic & Professional an Imprint ofChapman & Hall, London 1997, chapter 1, pages 1-97.

These free radical-grafting reactions are usually performed in thepresence of a free radical source such as a peroxide and a reactivemonomer, such as for example acrylic acid. However the use of freeradical sources such as peroxides may cause undesired side reactionsleading to problems during synthesis and processing (gel formation,crosslinking, molecular weight reduction) or during use. Typically thelong-term thermal stability is reduced and/or the polymer cannot anymorebe used in outdoor applications or in applications at elevatedtemperatures.

A further disadvantage of monomeric grafting processes is that thenumber of accessible monomers in a melt process is limited due tovolatility, thermal stability and side reactions e.g. homopolymerizationtakes place in parallel to the grafting reaction resulting inincompatible polymer mixtures without chemical bonding.

Furthermore it is very difficult or even impossible to obtain long chaingrafted structures from monomers via classical radical processes, as thelifetime of the growing radical chain is limited due to necessary hightemperatures of a melt process.

The instant invention avoids the disadvantages of the prior art, bypreparing in a first step a nitroxyl terminated oligomer or polymer, themolecular weight of which can be adjusted for example by theconcentration of the nitroxyl compound, the monomer used, the reactiontime (which is related to monomer conversion) and temperature. Thenitroxyl terminated oligomer or polymer acts in a second step as amacroinitiator and the polymer radical derived from the macroinitiatoris grafted onto the elastomeric or thermoplastic polymer or copolymer.

Another aspect of the invention is the manufacture of exact graftcopolymers with a clearly defined structure, e.g. pre-defined andsimilar branches. In addition, the number of branches can be simplycontrolled by the amount of nitroxyl-terminated oligomers/polymers addedto the thermoplastic or elastomeric polymer. Furthermore monomers ormonomer combinations are accessible as graft structures and also blockcopolymer structures, which are not accessible in a classical radicalpolymerization process.

Processes for the preparation of nitroxyl terminated oligomers orpolymers are known in the art.

For example U.S. Pat. No. 4,581,429 to Solomon et al., issued Apr. 8,1986, discloses a free radical polymerization process which controls thegrowth of polymer chains to produce short chain or oligomerichomopolymers and copolymers. The process employs an initiator having theformula (in part) R′R″N—O—X, where X is a free radical species capableof polymerizing unsaturated monomers and the radical R′R″N—O. isterminating the growing oligomer/polymer.

U.S. Pat. No. 5,322,912 to Georges et al. issued Jun. 21, 1994 disclosesa polymerization process using a free radical initiator, a polymerizablemonomer compound and a stable free radical agent of the basic structureR′R″N—O. for the synthesis of homopolymers and block copolymers whichare terminated by the nitroxyl radical.

More recently further nitroxyl radicals and nitroxyl ethers have beendescribed.

WO 98/13392 for example describes open chain alkoxyamine compounds,which have a symmetrical substitution pattern and are derived from NOgas or from nitroso compounds.

WO 96/24620 describes a polymerization process in which very specificstable free radical agents are used, such as for example

WO 98/30601 discloses specific nitroxyls based on imidazolidinons.

WO 98/44008 discloses specific nitroxyls based on morpholinones,piperazinones and piperazindiones.

These prior art nitroxyl radicals and nitroxyl ethers are all suitablefor the instant process.

The instant invention relates to a process for the preparation of agrafted thermoplastic or elastomeric polymer or copolymer, which processcomprises in a first step

A) the preparation of a nitroxyl terminated oligomer or polymer bycontrolled free radical polymerization of an ethylenically unsaturatedmonomer

-   -   a1) in the presence of a nitroxyl ether R′R″N—O—X wherein X is        selected such, that cleavage of the O—X bond occurs and a        radical X. is formed capable of initiating polymerization; or    -   a2) in the presence of a nitroxyl radical R′R″N—O. and a free        radical initiator capable of initiating polymerization; and in a        second step        B) heating, mixing and reacting the nitroxyl terminated oligomer        or polymer of step A) together with a thermoplastic or        elastomeric polymer or copolymer at a temperature of between        120° C. and 300° C.

For example the second step B) comprises heating, mixing and reactingthe nitroxyl terminated oligomer or polymer of step A) together with athermoplastic or elastomeric polymer or copolymer in the molten state ata temperature of between 150° C. and 300° C.

Suitable thermoplastic or elastomeric polymers and copolymers aresubsequently mentioned.

1. Polymers of monoolefins and diolefins, for example polypropylene,polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymersof cycloolefins, for instance of cyclopentene or norbornene,polyethylene (which optionally can be crosslinked), for example highdensity polyethylene (HDPE), high density and high molecular weightpolyethylene (HDPE-HMW), high density and ultrahigh molecular weightpolyethylene (HDPE-UHMW), medium density polyethylene (MDPE), lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE),(VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, preferably polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

-   -   a) radical polymerisation (normally under high pressure and at        elevated temperature).    -   b) catalytic polymerisation using a catalyst that normally        contains one or more than one metal of groups IVb, Vb, VIb or        VIII of the Periodic Table. These metals usually have one or        more than one ligand, typically oxides, halides, alcoholates,        esters, ethers, amines, alkyls, alkenyls and/or aryls that may        be either π- or σ-coordinated. These metal complexes may be in        the free form or fixed on substrates, typically on activated        magnesium chloride, titanium(III) chloride, alumina or silicon        oxide. These catalysts may be soluble or insoluble in the        polymerisation medium. The catalysts can be used by themselves        in the polymerisation or further activators may be used,        typically metal alkyls, metal hydrides, metal alkyl halides,        metal alkyl oxides or metal alkyloxanes, said metals being        elements of groups Ia, IIa and/or IIIa of the Periodic Table.        The activators may be modified conveniently with further ester,        ether, amine or silyl ether groups. These catalyst systems are        usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta),        TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1), for example mixtures ofpolypropylene with polyisobutylene, polypropylene with polyethylene (forexample PP/HDPE, PP/LDPE) and mixtures of different types ofpolyethylene (for example LDPE/HDPE).

3. Copolymers of monoolefins and diolefins with each other or with othervinyl monomers, for example ethylene/propylene copolymers, linear lowdensity polyethylene (LLDPE) and mixtures thereof with low densitypolyethylene (LDPE), propylene/but-1-ene copolymers,propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,ethylene/hexene copolymers, ethylene/methylpentene copolymers,ethylene/heptene copolymers, ethylene/octene copolymers,ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers(e.g. ethylene/norbornene like COC), ethylene/1-olefins copolymers,where the 1-olefin is gene-rated in-situ; propylene/butadienecopolymers, isobutylene/isoprene copolymers, ethylene/vinylcyclohexenecopolymers, ethylene/alkyl acrylate copolymers, ethylene/alkylmethacrylate copolymers, ethylene/vinyl acetate copolymers orethylene/acrylic acid copolymers and their salts (ionomers) as well asterpolymers of ethylene with propylene and a diene such as hexadiene,dicyclopentadiene or ethylidene-norbornene; and mixtures of suchcopolymers with one another and with polymers mentioned in 1) above, forexample polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinylacetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA),LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbonmonoxide copolymers and mixtures thereof with other polymers, forexample polyamides.

4. Hydrocarbon resins (for example C₅-C₉) including hydrogenatedmodifications thereof (e.g. tackifiers) and mixtures of polyalkylenesand starch.

Homopolymers and copolymers from 1.)-4.) may have any stereostructureincluding syndiotactic, isotactic, hemi-isotactic or atactic; whereatactic polymers are preferred. Stereoblock polymers are also included.

5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

6. Aromatic homopolymers and copolymers derived from vinyl aromaticmonomers including styrene, α-methylstyrene, all isomers of vinyltoluene, especially p-vinyltoluene, all isomers of ethyl styrene, propylstyrene, vinyl biphenyl, vinyl naphthalene, and vinyl anthracene, andmixtures thereof. Homopolymers and copolymers may have anystereostructure including syndiotactic, isotactic, hemi-isotactic oratactic; where atactic polymers are preferred. Stereoblock polymers arealso included.

6a. Copolymers including aforementioned vinyl aromatic monomers andcomonomers selected from ethylene, propylene, dienes, nitriles, acids,maleic anhydrides, maleimides, vinyl acetate and vinyl chloride oracrylic derivatives and mixtures thereof, for example styrene/butadiene,styrene/acrylonitrile, styrene/ethylene (interpolymers), styrene/alkylmethacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkylmethacrylate, styrene/maleic anhydride, styrene/acrylonitrile/methylacrylate; mixtures of high impact strength of styrene copolymers andanother polymer, for example a polyacrylate, a diene polymer or anethylene/propylene/diene terpolymer; and block copolymers of styrenesuch as styrene/butadiene/styrene, styrene/isoprene/styrene,styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene.

6b. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6.), especially includingpolycyclohexylethylene (PCHE) prepared by hydrogenating atacticpolystyrene, often referred to as polyvinylcyclohexane (PVCH).

6c. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6a.).

Homopolymers and copolymers may have any stereostructure includingsyndiotactic, isotactic, hemi-isotactic or atactic; where atacticpolymers are preferred. Stereoblock polymers are also included.

7. Graft copolymers of vinyl aromatic monomers such as styrene orα-methylstyrene, for example styrene on polybutadiene, styrene onpolybutadiene-styrene or polybutadiene-acrylonitrile copolymers; styreneand acrylonitrile (or methacrylonitrile) on polybutadiene; styrene,acrylonitrile and methyl methacrylate on polybutadiene; styrene andmaleic anhydride on polybutadiene; styrene, acrylonitrile and maleicanhydride or maleimide on polybutadiene; styrene and maleimide onpolybutadiene; styrene and alkyl acrylates or methacrylates onpolybutadiene; styrene and acrylonitrile on ethylene/propylene/dieneterpolymers; styrene and acrylonitrile on polyalkyl acrylates orpolyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadienecopolymers, as well as mixtures thereof with the copolymers listed under6), for example the copolymer mixtures known as ABS, MBS, ASA or AESpolymers.

8. Halogen-containing polymers such as polychloroprene, chlorinatedrubbers, chlorinated and brominated copolymer of isobutylene-isoprene(halobutyl rubber), chlorinated or sulfo-chlorinated polyethylene,copolymers of ethylene and chlorinated ethylene, epichlorohydrin homo-and copolymers, especially polymers of halogen-containing vinylcompounds, for example polyvinyl chloride, polyvinylidene chloride,polyvinyl fluoride, polyvinylidene fluoride, as well as copolymersthereof such as vinyl chloride/vinylidene chloride, vinyl chloride/vinylacetate or vinylidene chloride/vinyl acetate copolymers.

9. Polymers derived from α,β-unsaturated acids and derivatives thereofsuch as polyacrylates and polymethacrylates; polymethyl methacrylates,polyacrylamides and polyacrylonitriles, impact-modified with butylacrylate.

10. Copolymers of the monomers mentioned under 9) with each other orwith other unsaturated monomers, for example acrylonitrile/butadienecopolymers, acrylonitrile/alkyl acrylate copolymers,acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halidecopolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

11. Polymers derived from unsaturated alcohols and amines or the acylderivatives or acetals thereof, for example polyvinyl alcohol, polyvinylacetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate,polyvinyl butyral, polyallyl phthalate or polyallyl melamine; as well astheir copolymers with olefins mentioned in 1) above.

12. Homopolymers and copolymers of cyclic ethers such as polyalkyleneglycols, polyethylene oxide, polypropylene oxide or copolymers thereofwith bisglycidyl ethers.

13. Polyacetals such as polyoxymethylene and those polyoxymethyleneswhich contain ethylene oxide as a comonomer; polyacetals modified withthermoplastic polyurethanes, acrylates or MBS.

14. Polyphenylene oxides and sulfides, and mixtures of polyphenyleneoxides with styrene polymers or polyamides.

15. Polyurethanes derived from hydroxyl-terminated polyethers,polyesters or polybutadienes on the one hand and aliphatic or aromaticpolyisocyanates on the other, as well as precursors thereof.

16. Polyamides and copolyamides derived from diamines and dicarboxylicacids and/or from aminocarboxylic acids or the corresponding lactams,for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12,4/6, 12/12, polyamide 11, polyamide 12, aromatic polyamides startingfrom m-xylene diamine and adipic acid; polyamides prepared fromhexamethylenediamine and isophthalic or/and terephthalic acid and withor without an elastomer as modifier, for examplepoly-2,4,4-trimethylhexamethylene terephthalamide or poly-m-phenyleneisophthalamide; and also block copolymers of the aforementionedpolyamides with polyolefins, olefin copolymers, ionomers or chemicallybonded or grafted elastomers; or with polyethers, e.g. with polyethyleneglycol, polypropylene glycol or polytetramethylene glycol; as well aspolyamides or copolyamides modified with EPDM or ABS; and polyamidescondensed during processing (RIM polyamide systems).

17. Polyureas, polyimides, polyamide-imides, polyetherimids,polyesterimids, polyhydantoins and polybenzimidazoles.

18. Polyesters derived from dicarboxylic acids and diols and/or fromhydroxycarboxylic acids or the corresponding lactones, for examplepolyethylene terephthalate, polybutylene terephthalate,poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene naphthalate(PAN) and polyhydroxybenzoates, as well as block copolyether estersderived from hydroxyl-terminated polyethers; and also polyestersmodified with polycarbonates or MBS.

19. Polycarbonates and polyester carbonates.

20. Polyketones.

21. Polysulfones, polyether sulfones and polyether ketones.

22. Blends of the aforementioned polymers (polyblends), for examplePP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR,PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 andcopolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or PBT/PET/PC.

Preferably the thermoplastic or elastomeric polymer or copolymer isselected from the group consisting of a polyolefin and its copolymers,polystyrene and its block or graft copolymers and polymers or copolymersderived from 1,3-dienes.

More preferably the thermoplastic or elastomeric polymer or copolymer isselected from the group consisting of low density polyethylene (LDPE,LLDPE), high density polyethylene (HDPE), polypropylene (PP),polystyrene (PS), styrene-block copolymers (SI(S), SI, SB(S), ABS, ASA),ethylene-propylene-diene modified rubber (EPDM, EPM) and ethylenepropylene rubber (EPR), polybutylene (PB), polyisobutylene (PIB),poly-4-methylpentene-1 (PMP).

In a specific embodiment of the invention the thermoplastic orelastomeric polymer or copolymer contains unsaturated bonds.

Typically X is selected from the group consisting of

R₂₀ is hydrogen or C₁-C₁₂alkyl;the alkyl groups are unsubstituted or substituted with one or more —OH,—COOH or —C(O)R₂₀ groups; andthe aryl groups are phenyl or naphthyl which are unsubstituted orsubstituted with C₁-C₁₂alkyl, halogen, C₁-C₁₂alkoxy,C₁-C₁₂alkylcarbonyl, glycidyloxy, OH, —COOH or —COO(C₁-C₁₂)alkyl.

The nitroxylethers and nitroxyl radicals suitable for the invention areprincipally known from U.S. Pat. No. 4,581,429 or EP-A-621 878.Particularly useful are the open chain compounds described in WO98/13392, WO 99/03894 and WO 00/07981, the piperidine derivativesdescribed in WO 99/67298, GB 2335190 and GB 2 361 235 or theheterocyclic compounds described in GB 2342649 and WO 96/24620. Recentlyfurther nitroxyl radicals and nitroxyl ethers have been described in WO02/48205, WO02/48109 and WO 02/100831.

Also suitable are the compounds described by Hawker et al, Chem.Commun., 2001, 823-824

Some compounds are commercially available or can be prepared accordingto the aforementioned documents.

In a specific embodiment of the invention the nitroxyl-ether or thenitroxyl radical contains a structural element of formula (Ia) or (Ib)

G₁, G₂, G₃, G₄ are independently C₁-C₆alkyl or G₁ and G₂ or G₃ and G₄,or G₁ and G₂ and G₃ and G₄ together form a C₅-C₁₂cycloalkyl group;G₅, G₆ independently are H, C₁-C₁₈alkyl, phenyl, naphthyl or a groupCOOC₁-C₁₈alkyl.

In one embodiment of the invention components a1) and a2) are of formulaA, A′, B, B′ or O, O′

whereinG₁, G₂, G₃ and G₄ are independently alkyl of 1 to 4 carbon atoms, or G₁and G₂ together and G₃ and G₄ together, or G₁ and G₂ together or G₃ andG₄ together are pentamethylene;G₅ and G₆ are independently hydrogen or C₁-C₄ alkyl;m is 1, 2, 3 or 4R, if m is 1, is hydrogen, C₁-C₁₈alkyl which is uninterrupted orC₂-C₁₈alkyl which is interrupted by one or more oxygen atoms,cyanoethyl, benzoyl, glycidyl, a monovalent radical of an aliphaticcarboxylic acid having 2 to 18 carbon atoms, of a cycloaliphaticcarboxylic acid having 7 to 15 carbon atoms, or an α,β-unsaturatedcarboxylic acid having 3 to 5 carbon atoms or of an aromatic carboxylicacid having 7 to 15 carbon atoms, where each carboxylic acid can besubstituted in the aliphatic, cycloaliphatic or aromatic moiety by 1 to3 —COOZ₁₂ groups, in which Z₁₂ is H, C₁-C₂₀alkyl, C₃-C₁₂alkenyl,C₅-C₇cycloalkyl, phenyl or benzyl; orR is a monovalent radical of a carbamic acid or phosphorus-containingacid or a monovalent silyl radical;R, if m is 2, is C₂-C₁₂alkylene, C₄-C₁₂alkenylene, xylylene, a divalentradical of an aliphatic dicarboxylic acid having 2 to 36 carbon atoms,or a cycloaliphatic or aromatic dicarboxylic acid having 8-14 carbonatoms or of an aliphatic, cycloaliphatic or aromatic dicarbamic acidhaving 8-14 carbon atoms, where each dicarboxylic acid may besubstituted in the aliphatic, cycloaliphatic or aromatic moiety by oneor two —COOZ₁₂ groups; orR is a divalent radical of a phosphorus-containing acid or a divalentsilyl radical;R, if m is 3, is a trivalent radical of an aliphatic, cycloaliphatic oraromatic tricarboxylic acid, which may be substituted in the aliphatic,cycloaliphatic or aromatic moiety by —COOZ₁₂, of an aromatic tricarbamicacid or of a phosphorus-containing acid, or is a trivalent silylradical,R, if m is 4, is a tetravalent radical of an aliphatic, cycloaliphaticor aromatic tetracarboxylic acid;p is 1, 2 or 3,R₁₀₁ is C₁-C₁₂alkyl, C₅-C₇cycloalkyl, C₇-C₉phenylalkyl, C₂-C₁₈alkanoyl,C₃-C₅alkenoyl or benzoyl;when p is 1,R₁₀₂ is C₁-C₁₈alkyl, C₅-C₇cycloalkyl, C₂-C₈alkenyl unsubstituted orsubstituted by a cyano, carbonyl or carbamide group, or is glycidyl, agroup of the formula —CH₂CH(OH)—Z or of the formula —CO—Z— or —CONH—Zwherein Z is hydrogen, methyl or phenyl; orwhen p is 2,R₁₀₂ is C₂-C₁₂alkylene, C₆-C₁₂-arylene, xylylene, a—CH₂CH(OH)CH₂—O—B—O—CH₂CH(OH)CH₂— group, wherein B is C₂-C₁₀alkylene,C₅-C₁₅arylene or C₆-C₁₂cycloalkylene; or, provided that R₁₀₁ is notalkanoyl, alkenoyl or benzoyl, R₁₀₂ can also be a divalent acyl radicalof an aliphatic, cycloaliphatic or aromatic dicarboxylic acid ordicarbamic acid, or can be the group —CO—; or R₁₀₁ and R₁₀₂ togetherwhen p is 1 can be the cyclic acyl radical of an aliphatic or aromatic1,2- or 1,3-dicarboxylic acid; orR₁₀₂ is a group

where T₇ and T₈ are independently hydrogen, alkyl of 1 to 18 carbonatoms, or T₇ and T₈ together are alkylene of 4 to 6 carbon atoms or3-oxapentamethylene;when p is 3,R₁₀₂ is 2,4,6-triazinyl; andX is as defined above.

Preferably component a1) and a2) are of formula A, A′, B, B′ or O, O′

whereinm is 1,R is hydrogen, C₁-C₁₈alkyl which is uninterrupted or interrupted by oneor more oxygen atoms, cyanoethyl, benzoyl, glycidyl, a monovalentradical of an aliphatic carboxylic acid having 2 to 18 carbon atoms, ofa cycloaliphatic carboxylic acid having 7 to 15 carbon atoms, or anα,β-unsaturated carboxylic acid having 3 to 5 carbon atoms or of anaromatic carboxylic acid having 7 to 15 carbon atoms;p is 1;R₁₀₁ is C₁-C₁₂alkyl, C₅-C₇cycloalkyl, C₇-C₈aralkyl, C₂-C₁₈alkanoyl,C₃-C₅alkenoyl or benzoyl;R₁₀₂ is C₁-C₁₈alkyl, C₅-C₇cycloalkyl, C₂-C₈alkenyl unsubstituted orsubstituted by a cyano, carbonyl or carbamide group, or is glycidyl, agroup of the formula —CH₂CH(OH)—Z or of the formula —CO—Z or —CONH—Zwherein Z is hydrogen, methyl or phenyl;G₆ is hydrogen and G₅ is hydrogen or C₁-C₄alkyl,G₁, G₂, G₃ and G₄ are methyl; orG₁ and G₃ are methyl and G₂ and G₄ are ethyl or propyl or G₁ and G₂ aremethyl and G₃ and G₄ are ethyl or propyl; andX is selected from the group consisting of—CH₂-phenyl, CH₃CH-phenyl, (CH₃)₂C-phenyl, (C₅-C₆cycloalkyl)₂CCN,(CH₃)₂CCN, —CH₂CH═CH₂, CH₃CH—CH═CH₂ (C₁-C₄alkyl)CR₂₀—C(O)-phenyl,(C₁-C₄)alkyl-CR₂₀—C(O)—(C₁-C₄)alkoxy,(C₁-C₄)alkyl-CR₂₀—C(O)—(C₁-C₄)alkyl,(C₁-C₄)alkyl-CR₂₀—C(O)—N-di(C₁-C₄)alkyl,(C₁-C₄)alkyl-CR₂₀—C(O)—NH(C₁-C₄)alkyl, (C₁-C₄)alkyl-CR₂₀—C(O)—NH₂,whereinR₂₀ is hydrogen or (C₁-C₄)alkyl.

In a particularly preferred process G₂ and G₄ are ethyl, G₁ and G₃ aremethyl, G₆ is hydrogen and G₅ is methyl.

The alkyl radicals in the various substituents may be linear orbranched. Examples of alkyl containing 1 to 20 carbon atoms are methyl,ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl,2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl,undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl.

Alkenyl with 3 to 18 carbon atoms is a linear or branched radical as forexample propenyl, 2-butenyl, 3-butenyl, isobutenyl, n-2,4-pentadienyl,3-methyl-2-butenyl, n-2-octenyl, n-2-dodecenyl, iso-dodecenyl, oleyl,n-2-octadecenyl oder n-4-octadecenyl.

Preferred is alkenyl with 3 bis 12, particularly preferred with 3 to 6carbon atoms.

C₂-C₁₈alkyl interrupted by at least one O atom is for example—CH₂—CH₂—O—CH₂—CH₃, —CH₂—CH₂—O—CH₃— or—CH₂—CH₂—O—CH₂—CH₂—CH₂—O—CH₂—CH₃—. It is preferably derived frompolyethlene glycol. A general description is —((CH₂)_(a)—O)_(b)—H/CH₃,wherein a is a number from 1 to 6 and b is a number from 2 to 10.

C₃-C₁₂cycloalkyl is typically, cyclopropyl, cyclopentyl,methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl ortrimethylcyclohexyl.

C₆-C₁₀ aryl is for example phenyl or naphthyl, but also comprised areC₁-C₄alkyl substituted phenyl, C₁-C₄alkoxy substituted phenyl, hydroxy,halogen or nitro substituted phenyl.

Examples for alkyl substituted phenyl are ethylbenzene, toluene, xyleneand its isomers, mesitylene or isopropylbenzene. Halogen substitutedphenyl is for example dichlorobenzene or bromotoluene. Examples forC₆-C₁₂arylene can be derived from the above.

Alkoxy substituents are typically methoxy, ethoxy, propoxy or butoxy andtheir corresponding isomers.

C₇-C₉phenylalkyl is benzyl, phenylethyl or phenylpropyl.

When R is a monovalent radical of a carboxylic acid, R is, for example,an acetic acid, caproic acid, stearic acid, acrylic acid, methacrylicacid, benzoic acid or β-(3,5-di-tert-butyl-4-hydroxy-phenyl)-propionicacid radical.

When R is a monovalent silyl radical, Z₁₂ is, for example, a radical offormula —(C_(j)H_(2j))—Si(Z′)₂Z″ wherein j is an integer from the range2 to 5 and Z′ and Z″ are each independently of the other C₁-C₄alkyl orC₁-C₄alkoxy.

When R is a bivalent radical of a dicarboxylic acid, R is, for example,a malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid,sebacic acid, maleic acid, itaconic acid, phthalic acid, dibutylmalonicacid, dibenzylmalonic acid,butyl-(3,5-di-tert-butyl-4-hydroxybenzyl)-malonic acid orbicycloheptenedicarboxylic acid radical.

When R is a trivalent radical of a tricarboxylic acid, R is, forexample, a trimellitic acid, citric acid or nitrilotriacetic acidradical.

When R is a tetravalent radical of a tetracarboxylic acid, R is, forexample, the tetravalent radical of butane-1,2,3,4-tetracarboxylic acidor of pyromellitic acid.

When R is a bivalent radical of a dicarbamic acid, R is, for example, ahexamethylene-dicarbamic acid or 2,4-toluylene-dicarbamic acid radical.

C₁-C₁₈alkanoyl is for example, formyl, propionyl, butyryl, octanoyl,dodecanoyl but preferably acetyl and C₃-C₅alkenoyl is in particularacryloyl.

Particularly suitable nitroxylethers and nitroxyl radicals are those offormulae

Also suitable are the following compounds:

Most preferred are following compounds

The free radical initiator of component a2) is preferably a bis-azocompound, a peroxide, a perester or a hydroperoxide.

Specific preferred radical sources are 2,2′-azobisisobutyronitrile,2,2′-azobis(2-methyl-butyronitrile),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),1,1′-azobis(1-cyclohexanecarbonitrile), 2,2′-azobis(isobutyramide)dihydrate, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile,dimethyl-2,2′-azobisisobutyrate, 2-(carbamoylazo)isobutyronitrile,2,2′-azobis(2,4,4-trimethylpentane), 2,2′-azobis(2-methylpropane),2,2′-azobis(N,N′-dimethyleneisobutyramidine), free base orhydrochloride, 2,2′-azobis(2-amidinopropane), free base orhydrochloride,2,2′-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} or2,2′-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide;acetyl cyclohexane sulphonyl peroxide, diisopropyl peroxy dicarbonate,t-amyl perneodecanoate, t-butyl perneodecanoate, t-butyl perpivalate,t-amylperpivalate, bis(2,4-dichlorobenzoyl)peroxide, diisononanoylperoxide, didecanoyl peroxide, dioctanoyl peroxide, dilauroyl peroxide,bis(2-methylbenzoyl) peroxide, disuccinic acid peroxide, diacetylperoxide, dibenzoyl peroxide, t-butyl per 2-ethylhexanoate,bis-(4-chlorobenzoyl)-peroxide, t-butyl perisobutyrate, t-butylpermaleinate, 1,1-bis(t-butylperoxy)3,5,5-trimethylcyclohexane,1,1-bis(t-butylperoxy)cyclohexane, t-butyl peroxy isopropyl carbonate,t-butyl perisononaoate, 2,5-dimethylhexane 2,5-dibenzoate, t-butylperacetate, t-amyl perbenzoate, t-butyl perbenzoate,2,2-bis(t-butylperoxy) butane, 2,2 bis (t-butylperoxy) propane, dicumylperoxide, 2,5-dimethylhexane-2,5-di-t-butylperoxide, 3-t-butylperoxy3-phenylphthalide, di-t-amyl peroxide, α,α′-bis(t-butylperoxyisopropyl)benzene, 3,5-bis(t-butylperoxy)3,5-dimethyl 1,2-dioxolane,di-t-butyl peroxide, 2,5-dimethylhexyne-2,5-di-t-butylperoxide,3,3,6,6,9,9-hexamethyl 1,2,4,5-tetraoxa cyclononane, p-menthanehydroperoxide, pinane hydroperoxide, diisopropylbenzenemono-α-hydroperoxide, cumene hydroperoxide or t-butyl hydroperoxide.

Azo initiators and peroxides are most preferred.

Preferably the nitroxylether of component a1) or the nitroxyl radical ofcomponent a2) is present in an amount of from 0.001 mol-% to 20 mol-%,more preferably of from 0.01 mol-% to 10 mol-% and most preferably offrom 0.1 mol-% to 5 mol-%, based on the monomer or monomer mixture.

When monomer mixtures are used mol-% is calculated on an averagemolecular weight.

The free radical initiator is preferably present in an amount of from0.001 mol-% to 20 mol-%, more preferably of from 0.01 mol-% to 10 mol-%and most preferably of from 0.1 mol-% to 5 mol-%, based on the monomeror monomer mixture.

The molar ratio of free radical initiator to stable free nitroxylradical is preferably from 20:1 to 1:2, more preferably from 10:1 to1:2.

Preferably the ethylenically unsaturated monomer or oligomer is selectedfrom the group consisting of styrene, substituted styrene, conjugateddienes, vinyl acetate, vinylpyrrolidone, vinylimidazole, maleicanhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acid salts,(alkyl)acrylic esters, (meth)acrylonitriles, (alkyl)acrylamides, vinylhalides or vinylidene halides.

Preferably the ethylenically unsaturated monomer is a compound offormula CH₂═C(R_(a))—(C═Z)—R_(b), wherein R_(a) is hydrogen orC₁-C₄alkyl, R_(b) is NH₂, O⁻(Me⁺), glycidyl, unsubstituted C₁-C₁₈alkoxy,C₂-C₁₀₀alkoxy interrupted by at least one N and/or O atom, orhydroxy-substituted C₁-C₁₈alkoxy, unsubstituted C₁-C₁₈alkylamino,di(C₁-C₁₈alkyl)amino, hydroxy-substituted C₁-C₁₈alkylamino orhydroxy-substituted di(C₁-C₁₈alkyl)amino, —O—CH₂—CH₂—N(CH₃)₂ or—O—CH₂—CH₂—N⁺H(CH₃)₂An⁻;

An⁻ is an anion of a monovalent organic or inorganic acid;

Me is a monovalent metal atom or the ammonium ion.

Z is oxygen or sulfur.

Examples of acids from which the anion An⁻ is derived areC₁-C₁₂carboxylic acids, organic sulfonic acids such as CF₃SO₃H orCH₃SO₃H, mineralic acids such as HCl, HBr or HI, oxo acids such as HClO₄or complex acids such as HPF₆ or HBF₄.

Examples for R_(a) as C₂-C₁₀₀alkoxy interrupted by at least one O atomare of formula

wherein R_(c) is C₁-C₂₅alkyl, phenyl or phenyl substituted byC₁-C₁₈alkyl, R_(d) is hydrogen or methyl and v is a number from 1 to 50.These monomers are for example derived from non ionic surfactants byacrylation of the corresponding alkoxylated alcohols or phenols. Therepeating units may be derived from ethylene oxide, propylene oxide ormixtures of both.

Further examples of suitable acrylate or methacrylate monomers are givenbelow.

An⁻, wherein An⁻ and R_(a) have the meaning as defined above and R_(e)is methyl or benzyl. An⁻ is preferably Cl⁻, Br⁻ or ⁻O₃S—CH₃.

Further acrylate monomers are

Examples for suitable monomers other than acrylates are

Preferably R_(a) is hydrogen or methyl, R_(b) is NH₂, gycidyl,unsubstituted or with hydroxy substituted C₁-C₄alkoxy, unsubstitutedC₁-C₄alkylamino, di(C₁-C₄alkyl)amino, hydroxy-substitutedC₁-C₄alkylamino or hydroxy-substituted di(C₁-C₄alkyl)amino; and Z isoxygen.

More preferred the ethylenically unsaturated monomer is an acrylic acidester, acrylamide, acrylnitrile, methacrylic acid ester, methacrylamide,methacrylonitrile, maleic acid anhydride or styrene.

Acrylic acid esters and methacrylic acid esters are typicallyC₁-C₁₈alkyl esters.

Step A) of the instant process can also be carried out with a mixture ofmonomers, resulting in a nitroxyl terminated random copolymer. It is,however, also possible to carry out step A) in a consecutive way withdifferent monomers, resulting in a block copolymer. The resultingmacroinitiator can therefore be a homopolymer, a random copolymercontaining two or more different monomers or a block copolymer, whichmay be a diblock, a triblock or a multiblock copolymer. The secondmonomer can also be added when still the first monomer is present inorder to form tapered structures.

Random Copolymers are for example poly(styrene-co-acrylonitrile).

Block copolymers are, for example, block copolymers of polystyrene andpolyacrylate (e.g., poly(styrene-co-acrylate) orpoly(styrene-co-acrylate-co-styrene).

The scission of the O—C bond can be effected by ultrasonic treatment,heating or exposure to electromagnetic radiation, ranging from γ tomicrowaves.

The scission of the O—X bond is preferably effected by heating and takesplace at a temperature of between 50° C. and 180° C., more preferablyfrom 80° C. to 150° C.

The reaction temperature for step A) is typically between 50° C. and180° C., more preferably between 80° C. and 150° C. Controlledpolymerization is usually carried out under normal pressure. It is,however, possible for example when polymerization is carried out in thepresence of water or in the presence of volatile monomers that apressure from 1 bar to 20 bar is applied.

The reaction time for step A) can vary from several minutes to somehours, depending on the desired degree of monomer to polymer conversion,the monomer itself, reaction temperature and the desired molecularweight. Typical are 30 minutes to 24 hours, in particular 1 hour to 12hours.

The nitroxyl terminated oligomer or polymer of step A) can be isolatedand purified according to standard procedures of polymer chemistry.Preferably not reacted monomers are removed by precipitation of thepolymer in an inert medium, by evaporation, by degassing or extraction,so that the macroinitiator is essentially free of monomer when step B)is applied. The drying temperature should be below 100° C. to avoid O—Rbond cleavage. At ambient temperature the macroinitiator can be storedfor a long time without loosing its activity.

The process step A) may be carried out in the presence of an organicsolvent or in the presence of water or in mixtures of organic solventsand water. Additional cosolvents or surfactants, such as glycols orammonium salts of fatty acids, may be present. Other suitable cosolventsare described hereinafter.

If organic solvents are used, suitable solvents or mixtures of solventsare typically pure alkanes (hexane, heptane, octane, isooctane),cycloalkanes (decaline), aromatic hydrocarbons (benzene, toluene,xylene, tert-butylbenzene), halogenated hydrocarbons (chlorobenzene,dichlorobenzene), alkanols (methanol, ethanol, ethylene glycol, ethyleneglycol monomethyl ether), esters (ethyl acetate, propyl, butyl or hexylacetate) and ethers (diethyl ether, dibutyl ether, anisol, ethyleneglycol dimethyl ether), or mixtures thereof.

The aqueous polymerization reactions can be supplemented with awater-miscible or hydrophilic cosolvent to help ensure that the reactionmixture remains a homogeneous single phase throughout the monomerconversion. Any water-soluble or water-miscible cosolvent may be used,as long as the aqueous solvent medium is effective in providing asolvent system which prevents precipitation or phase separation of thereactants or polymer products until after all polymerization reactionshave been completed. Exemplary cosolvents useful in the presentinvention may be selected from the group consisting of aliphaticalcohols, glycols, ethers, glycol ethers, pyrrolidines, N-alkylpyrrolidinones, N-alkyl pyrrolidones, polyethylene glycols,polypropylene glycols, amides, carboxylic acids and salts thereof,esters, organosulfides, sulfoxides, sulfones, alcohol derivatives,hydroxyether derivatives such as butyl carbitol or cellosolve, aminoalcohols, ketones, and the like, as well as derivatives thereof andmixtures thereof. Specific examples include methanol, ethanol, propanol,dioxane, ethylene glycol, propylene glycol, diethylene glycol, glycerol,dipropylene glycol, tetrahydrofuran, and other water-soluble orwater-miscible materials, and mixtures thereof. When mixtures of waterand water-soluble or water-miscible organic liquids are selected as theaqueous reaction media, the water to cosolvent weight ratio is typicallyin the range of about 100:0 to about 10:90.

Emulsion polymerizations are a matter of particular interest. Thepolymers are essentially insoluble in the aqueous phase and form finelydistributed droplets therein. The addition of dispersing agents such asfor example sodium dodecylsulfate is in many cases necessary to achievesuch stable droplets and micelles. Examples of dispersing agents are forexample given in “Ullmann Enzyklopädie der technischen Chemie, Bd.10, 4.Auflage, Verlag Chemie, Weinheim (1975), page 449”.

Several variations are known in the prior art, for example emulsifierfree emulsion polymerization, mini emulsion polymerization and microemulsion polymerization. These variations are characterized by changesof kind and amount of the emulsifier and initiator system leading todifferent polymer products, especially with regard to molecular weight,polymer particle size and their distributions.

For example the aqueous phase is from 25 to 95% preferably from 40 to80% and more preferred from 45 to 75% by weight, based on the totalmixture.

Optionally other water miscible solvents may be present usually lessthan 10% by weight based on the water content. Exemplary cosolvents maybe selected from the group consisting of aliphatic alcohols, glycols,ethers, glycol ethers, pyrrolidines, N-alkyl pyrrolidinones, N-alkylpyrrolidones, polyethylene glycols, polypropylene glycols, amides,carboxylic acids and salts thereof, esters, organosulfides, sulfoxides,sulfones, alcohol derivatives, hydroxyether derivatives such as butylcarbitol or cellosolve, amino alcohols, ketones, and the like, as wellas derivatives thereof and mixtures thereof. Specific examples includemethanol, ethanol, propanol, dioxane, ethylene glycol, propylene glycol,diethylene glycol, glycerol, dipropylene glycol, tetrahydrofuran, andother water-soluble or water-miscible materials, and mixtures thereof.

Preferred are water, water alcohol mixtures, water ethylene glycol orpropylene glycol mixtures, water acetone, water tetrahydrofurane, orwater dimethylformamide mixtures.

Preferably the solids content of the resulting polymer dispersion isbetween 15-60% by weight.

Emulsion polymerization is particularly suitable to built up graftpolymers with uniform graft arm lengths and even new graft polymers.

The average particle diameter of the dispersed polymer particles ispreferably from 25 nm to 1000 nm, more preferably 200 nm to 700 nm.Particle size may for example be measured by a high speed centrifuge orby photon correlation spectroscopy. The particle size distribution maybe monomodal or bimodal.

The process of emulsion polymerization per se is known and for exampledescribed in WO 99/00426 or in WO 00/50480. It may be carried out as abatch process or in a continuous or semi continuous process.

Suitable surfactants or surface active compounds which may be added areknown in the art. The amounts typically used range from 0.01% by weightto 10% by weight, based on the monomer or monomers.

Suitable surface active compounds are protective colloids such aspolyvinylalcohols starch, cellulose derivatives or copolymers containingvinylpyrrolidone. Further examples are given in “Houben-Weyl, Methodender Organischen Chemie, Band XIV/1, Makromolekulare Stoffe, G. ThiemeVerlag Stuttgart 1961, 411-420”.

Typical surfactants useful in the present invention are of nonionic,cationic or anionic type.

Examples for anionic surfactants are alkali and ammonium salts ofC₁₂-C₁₈alkylsulfonic acid, dialkyl esters of succinic acid or sulfuricacid halfesters of ethoxylated alkanoles. These compounds are known forexample from U.S. Pat. No. 4,269,749 and largely items of commerce, suchas under the trade name Dowfax® 2A1 (Dow Chemical Company).

Nonionic surfactants are for example aliphatic or araliphatic compoundssuch as ethoxylated phenols (mon, di, tri) with an ethoxylation degreeof 3 to 50 and alkyl groups in the range from C₄-C₉, ethoxylated longchain alcohols or polyethyleneoxide/polypropyleneoxide block copolymers.

The emulsion polymerization may be carried out as seed free process oraccording to a seed-latex process which seed latex may also be preparedin situ. Such processes are known and for example described in WO02/024761, EP-A-614 922 or in EP-A-567 812.

The (co)polymers of step A) may have a number average molecular weightfrom 1 000 to 100 000 Dalton, preferably from 1000 to 50 000 Dalton and,more preferably, from 1000 to 20 000 Dalton. The number averagemolecular weight may be determined by size exclusion chromatography(SEC), matrix assisted laser desorption/ionization mass spectrometry(MALDI-MS) or, if the initiator carries a group which can be easilydistinguished from the monomer(s), by NMR spectroscopy or otherconventional methods.

The polymers or copolymers of step A) have preferably a polydispersityof from 1.0 to 2.0, more preferably of from 1.1 to 1.8, and mostpreferably from 1.1 to 1.5.

The reaction of the 2^(nd) step may be carried out in solution,dispersion or preferably in the melt. If a solution process is carriedout, the polymer to be grafted and the nitroxyl-terminatedoligomer/polymer are preferably both soluble in the solvent. The solventitself should be inert (low transmission rate) and the boiling point hasto be high enough. Typical solvents for the modification of e.g.polyolefines or polyolefinic elastomers include xylene, decaline,tert-butylbenzene, chloro-/dichlorobenzene.

It is, however preferred, that the 2^(nd) step is carried out in themelt. The temperature applied in the second step is in general between120° C. and 300° C. and must be such, that the thermoplastic orelastomeric polymer or copolymer can be processed or mixed in a typicalpolymer processing device such as a mixer, kneader or extruder. Apreferred temperature range for the melt process is between 150° C. and300° C., in particular between 150° C. and 280° C.

The reaction time for step B) depends on the reactivity of themacroinitiator and the desired amount of grafted polymer radicals.Typical reaction times are from a few minutes to hours. Preferably thereaction time is from 1 min to 1 h, most preferably from 2 min to 20min.

When the macroinitiator is added to the thermoplastic or elastomericpolymer or copolymer no additional monomer has normally to be added. Itis, however, possible for synthetic or technical reasons to add monomersor unfunctionalized homopolymers to achieve desired properties. If thisis done, preferably low amounts are added.

When a melt process is carried out in step B), the temperature appliedin the second reaction step B) depends on the polymer and is for example50° to 150° C. above the glass transition temperature (Tg) for amorphouspolymers and 20° to 180° C. above the melting temperature (Tm) forsemi-crystalline polymers. Typical are following temperatures:

low density polyethylene LDPE 170-260° C. high density polyethylene HDPE180-270° C. polypropylene PP 180-280° C. polystyrene PS 190-280° C.styrene-block copolymers SB(S) 160-260° C. ethylene-propylene-dienemodified EPDM 160-260° C. ethylene propylene rubber EPR 160-260° C.

In a preferred process the temperature in the second step B) is from170° C. to 280° C., more preferred from 190° C. to 280° C. Theprocessing temperature shall be adjusted to achieve a homogeneouspolymer melt and to avoid thermal degradation.

Step B) of the process may be performed in any reactor suitable formixing a polymer melt. Preferably the reactor is an extruder, mixing orkneading apparatus as for example described in “Handbuch derKunststoffextrusion” Vol. I, editor F. Hensen, W. Knappe and H. Potente,1989, pages 3-7. If an extruder is used the process may be described asreactive extrusion process. Examples of reactive extrusion equipment andprocesses are given by G. H. Hu et al., in “Reactive Modifiers forPolymers”, first edition, Blackie Academic & Professional an Imprint ofChapman & Hall, London 1997, chapter 1, pages 1-97.

The addition to the polymer can be effected in any customary mixingapparatus in which the polymer is melted and mixed with the additives.Suitable apparatus are known to those skilled in the art, such apparatusbeing predominantly mixers, kneaders and extruders.

The process is preferably carried out, by adding the compounds duringprocessing in an extruder.

Especially preferred processing apparatus include single-screwextruders, double-screw extruders with screws rotating in the same oropposite directions, planetary roller extruders, ring extruders orco-kneaders. It is also possible to use processing machines whichcontain at least one degassing zone and which can be placed underreduced pressure to remove by-products or volatile residues.

Suitable extruders and kneaders are described inter alia in Handbuch derKunststoff-extrusion, Vol. 1 Grundlagen, Eds. F. Hensen, W. Knappe, HPotente, 1989, pages 3-7, ISBN:3-446-14339-4 (Vol. 2 Extrusionsanlagen1986, ISBN 3-446-14329-7).

By way of example, the screw length is 1-60 times the screw diameter andpreferably 35-48 times the screw diameter. The screw speed is preferably10-600 revolutions per minute (rev/min) and more especially 25-300rev/min.

The maximum throughput is dependent upon the screw diameter, speed anddriving power. The process of the present invention can also be carriedout at lower than the maximum throughput by varying the mentionedparameters or by operating with feed weighing devices.

If a plurality of components is added, these can be added premixed orindividually or in the form of a masterbatch or concentrate.

The mixtures are to be exposed to elevated temperature for a sufficientperiod of time for the desired grafting yield to occur. The temperatureis above the softening temperature in the case of amorphous polymers orthe melting temperature in the case of crystalline polymers. It is notalways necessary that the grafting takes place to the maximum extentpossible. Preferably at last 50% is grafted after the reaction step B.

Preferably, if an extruder is used, a reduced pressure of less than 200mbar is applied during extrusion.

Preferably the nitroxyl terminated polymer or oligomer of step A) isadded to the thermoplastic or elastomeric polymer or copolymer in anamount from 0.1% to 50% by weight, based on the weight of thethermoplastic or elastomeric polymer or copolymer.

Further aspects of the invention are a grafted thermoplastic orelastomeric polymer or copolymer obtained by the above process and theuse of a nitroxyl terminated polymer or oligomer for the preparation ofa grafted thermoplastic or elastomeric polymer or copolymer comprisingheating mixing and reacting the nitroxyl terminated oligomer or polymertogether with a thermoplastic or elastic polymer or copolymer at atemperature of between 120° C. and 300° C.

Radical generators such as peroxides/hydroperoxides, bisazo compounds orhydroxylamine-esters (as for example disclosed in WO 01/90113) can befurther added in step B), in order to increase the radical concentrationon the thermoplastic or elastomeric polymer or copolymer. The radicalgenerator is selected according to its decomposition temperature and theintended reaction temperature. Suitable radical generators are forexample, dicumylperoxide,2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, di-tert-butylperoxide,2,5-(bis(tert-butylperoxy)-2,5-dimethylhexane, tert-butyl-cumylperoxide,bis(tert-butylperoxyisopropyl)benzene,butyl-4,4-bis(tert-butylperoxy)valerate, tert-butyl hydroperoxide andthe like.

There may be further additives added during step B) of the process, suchas processing stabilizers, light or heat stabilizers, fillers pigmentsand the like.

1. Antioxidants

1.1. Alkylated monophenols, for example2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol,2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are linearor branched in the side chains, for example 2,6-di-nonyl-4-methylphenol,2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol,2,4-dimethyl-6-(1′-methylheptadec-1′-yl)phenol,2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example2,4-dioctylthiomethyl-6-tert-butylphenol,2,4-dioctylthiomethyl-6-methylphenol,2,4-dioctylthiomethyl-6-ethylphenol,2,6-di-dodecylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones, for example2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone,2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenylstearate, bis(3,5-di-tert-butyl-4-hydroxyphenyl)adipate.

1.4. Tocopherols, for example α-tocopherol, β-tocopherol, γ-tocopherol,δ-tocopherol and mixtures thereof (vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol),4,4′-thiobis(6-tert-butyl-3-methylphenol),4,4′-thiobis(6-tert-butyl-2-methylphenol),4,4′-thiobis(3,6-di-sec-amylphenol),4,4′-bis(2,6-dimethyl-4-hydroxyphenyl)-disulfide.

1.6. Alkylidenebisphenols, for example2,2′-methylenebis(6-tert-butyl-4-methylphenol),2,2′-methylenebis(6-tert-butyl-4-ethylphenol),2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)-phenol],2,2′-methylenebis(4-methyl-6-cyclohexylphenol),2,2′-methylenebis(6-nonyl-4-methylphenol),2,2′-methylenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4,6-di-tert-butyl-phenol),2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol],4,4′-methylenebis(2,6-di-tert-butylphenol),4,4′-methylenebis(6-tert-butyl-2-methylphenol),1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane,ethylene glycol bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate],bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene,bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane,2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,2,2-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane,1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. O-, N- and S-benzyl compounds, for example3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether,octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate,tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate,tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine,bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,bis(3,5-di-tert-butyl-4-hydroxy-benzyl)sulfide,isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzylated malonates, for exampledioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate,di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate,di-dodecylmercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9. Aromatic hydroxybenzyl compounds, for example1,3,5-tris(3,5-di-tert-butyl-4-hydroxy-benzyl)-2,4,6-trimethylbenzene,1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.10. Triazine compounds, for example2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxy-anilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,2,4,6-tris-(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,2,4,6-tris-(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-hexahydro-1,3,5-triazine,1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.

1.11. Benzylphosphonates, for exampledimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate,diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, thecalcium salt of the monoethyl ester of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12. Acylaminophenols, for example 4-hydroxylauranilide,4-hydroxystearanilide, octylN-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol,i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acidwith mono- or polyhydric alcohols, e.g. with methanol, ethanol,n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethyleneglycol, diethylene glycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis-(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane;3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]-undecane.

1.15. Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono-or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g.N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamide,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamide,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazide,N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide(Naugard®XL-1, supplied by Uniroyal).

1.18. Ascorbic acid (vitamin C)

1.19. Aminic antioxidants, for exampleN,N′-di-isopropyl-p-phenylenediamine,N,N′-di-sec-butyl-p-phenylenediamine,N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine,N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine,N,N′-bis(1-methylheptyl)-p-phenylenediamine,N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine,N,N′-bis(2-naphthyl)-p-phenylenediamine,N-isopropyl-N′-phenyl-p-phenylenediamine,N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine,N-cyclohexyl-N′-phenyl-p-phenylenediamine,4-(p-toluenesulfamoyl)diphenylamine,N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine,N-allyldiphenylamine, 4-isopropoxydiphenylamine,N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine,N-phenyl-2-naphthylamine, octylated diphenylamine, for examplep,p′-di-tert-octyldiphenylamine, 4-n-butyl-aminophenol,4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol,4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine,2,6-di-tert-butyl-4-dimethylamino-methylphenol,2,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane,N,N,N′,N′-tetramethyl-4,4′-diaminodiphenylmethane,1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenyl-amino)propane,(o-tolyl)biguanide, bis[4-(1′,3′-dimethylbutyl)phenyl]amine,tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- anddialkylated tert-butyl/tert-octyldiphenylamines, a mixture of mono- anddialkylated nonyldiphenylamines, a mixture of mono- and dialkylateddodecyldiphenylamines, a mixture of mono- and dialkylatedisopropyl/isohexyl-diphenylamines, a mixture of mono- and dialkylatedtert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine,phenothiazine, a mixture of mono- and dialkylatedtert-butyl/tert-octylphenothiazines, a mixture of mono- and dialkylatedtert-octylphenothiazines, N-allylphenothiazine,N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene,N,N-bis(2,2,6,6-tetramethylpiperid-4-yl-hexamethylenediamine,bis(2,2,6,6-tetramethylpiperid-4-yl)sebacate,2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

2. UV Absorbers and Light Stabilisers

2.1. 2-(2′-Hydroxyphenyl)benzotriazoles, for example2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,2-(3′,5′-bis(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethylhexyl-oxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonyl-ethyl)phenyl)benzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxy-phenyl)benzotriazole,2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol];the transesterification product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazolewith polyethylene glycol 300; [R—CH₂CH₂—COO—CH₂CH₂

₂, where R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-ylphenyl,2-[2′-hydroxy-3′-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)phenyl]-benzotriazole;2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)phenyl]benzotriazole.

2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxyand 2′-hydroxy-4,4′-dimethoxy derivatives.

2.3. Esters of substituted and unsubstituted benzoic acids, for example4-tert-butylphenyl salicylate, phenyl salicylate, octylphenylsalicylate, dibenzoyl resorcinol, bis(4-tert-butylbenzoyl)resorcinol,benzoyl resorcinol, 2,4-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctylα-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methylα-cyano-β-methyl-p-methoxycinnamate, butylα-cyano-β-methyl-p-methoxycinnamate, methylα-carbomethoxy-p-methoxycinnamate andN-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of2,2′-thiobis[4-(1,1,3,3-tetramethyl-butyl)phenol], such as the 1:1 or1:2 complex, with or without additional ligands such as n-butylamine,triethanolamine or N-cyclohexyldiethanolamine, nickeldibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g. themethyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonicacid, nickel complexes of ketoximes, e.g. of2-hydroxy-4-methylphenylundecylketoxime, nickel complexes of1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additionalligands.

2.6. Sterically hindered amines, for examplebis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(2,2,6,6-tetramethyl-4-piperidyl)succinate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, linear or cyclic condensates ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-triazine,tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)-malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cycliccondensates ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)-ethane, the condensate of2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, amixture of 4-hexadecyloxy- and4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensate ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensate of1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine aswell as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No.[136504-96-6]); a condensate of 1,6-hexanediamine and2,4,6-trichloro-1,3,5-triazine as well as N,N-dibutylamine and4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [192268-64-7]);N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide,N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide,2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, areaction product of7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro-[4,5]decaneand epichlorohydrin,1,1-bis(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene,N,N′-bis-formyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine,a diester of 4-methoxymethylenemalonic acid with1,2,2,6,6-pentamethyl-4-hydroxypiperidine,poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, areaction product of maleic acid anhydride-α-olefin copolymer with2,2,6,6-tetramethyl-4-aminopiperidine or1,2,2,6,6-pentamethyl-4-aminopiperidine.

2.7. Oxamides, for example 4,4′-dioctyloxyoxanilide,2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide,2,2′-didodecyloxy-5,5′-di-tert-butoxanilide, 2-ethoxy-2′-ethyloxanilide,N,N′-bis(3-dimethylaminopropyl)oxamide,2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, mixtures of o- andp-methoxy-disubstituted oxanilides and mixtures of o- andp-ethoxy-disubstituted oxanilides.

2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine,2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine,2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine,2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine,2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

3. Metal deactivators, for example N,N′-diphenyloxamide,N-salicylal-N′-salicyloyl hydrazine, N,N′-bis(salicyloyl)hydrazine,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl dihydrazide,oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide,N,N′-diacetyladipoyl dihydrazide, N,N′-bis(salicyloyl)oxalyldihydrazide, N,N′-bis(salicyloyl)thiopropionyl dihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite,diphenylalkyl phosphites, phenyldialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite,distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, diisodecyl pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,bis(2,4-di-cumylphenyl)pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,diisodecyloxypentaerythritol diphosphite,bis(2,4-di-tert-butyl-6-methylphenyl)-pentaerythritol diphosphite,bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearylsorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)4,4′-biphenylene diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin,bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite,bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite,6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin,2,2′,2″-nitrilo-[triethyltris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite],2-ethylhexyl(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite,5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphirane.

The following phosphites are especially preferred:

Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos®168, Ciba-Geigy),tris(nonylphenyl) phosphite,

5. Hydroxylamines, for example N,N-dibenzylhydroxylamine,N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine,N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine,N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine,N-hexadecyl-N-octadecylhydroxylamine,N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derivedfrom hydrogenated tallow amine.

6. Nitrones, for example N-benzyl-alpha-phenylnitrone,N-ethyl-alpha-methylnitrone, N-octyl-alpha-heptylnitrone,N-lauryl-alpha-undecylnitrone, N-tetradecyl-alpha-tridecylnitrone,N-hexadecyl-alpha-pentadecylnitrone,N-octadecyl-alpha-heptadecylnitrone,N-hexadecyl-alpha-heptadecylnitrone,N-ocatadecyl-alpha-pentadecylnitrone,N-heptadecyl-alpha-heptadecylnitrone,N-octadecyl-alpha-hexadecylnitrone, nitrone derived fromN,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

7. Thiosynergists, for example dilauryl thiodipropionate or distearylthiodipropionate.

8. Peroxide scavengers, for example esters of β-thiodipropionic acid,for example the lauryl, stearyl, myristyl or tridecyl esters,mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zincdibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritoltetrakis(β-dodecylmercapto)propionate.

9. Polyamide stabilisers, for example copper salts in combination withiodides and/or phosphorus compounds and salts of divalent manganese.

10. Basic co-stabilisers, for example melamine, polyvinylpyrrolidone,dicyandiamide, triallyl cyanurate, urea derivatives, hydrazinederivatives, amines, polyamides, polyurethanes, alkali metal salts andalkaline earth metal salts of higher fatty acids, for example calciumstearate, zinc stearate, magnesium behenate, magnesium stearate, sodiumricinoleate and potassium palmitate, antimony pyrocatecholate or zincpyrocatecholate.

11. Nucleating agents, for example inorganic substances, such as talcum,metal oxides, such as titanium dioxide or magnesium oxide, phosphates,carbonates or sulfates of, preferably, alkaline earth metals; organiccompounds, such as mono- or polycarboxylic acids and the salts thereof,e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodiumsuccinate or sodium benzoate; polymeric compounds, such as ioniccopolymers (ionomers). Especially preferred are1,3:2,4-bis(3′,4′-dimethylbenzylidene)sorbitol,1,3:2,4-di(paramethyldibenzylidene)sorbitol, and1,3:2,4-di(benzylidene)sorbitol.

12. Fillers and reinforcing agents, for example calcium carbonate,silicates, glass fibres, glass bulbs, asbestos, talc, kaolin, mica,barium sulfate, metal oxides and hydroxides, carbon black, graphite,wood flour and flours or fibers of other natural products, syntheticfibers.

13. Other additives, for example plasticisers, lubricants, emulsifiers,pigments, rheology additives, catalysts, flow-control agents, opticalbrighteners, flameproofing agents, antistatic agents and blowing agents.

14. Benzofuranones and indolinones, for example those disclosed in U.S.Pat. No. 4,325,863; U.S. Pat. No. 4,338,244; U.S. Pat. No. 5,175,312;U.S. Pat. No. 5,216,052; U.S. Pat. No. 5,252,643; DE-A-4316611;DE-A-4316622; DE-A-4316876; EP-A-0589839 or EP-A-0591102 or3-[4-(2-acetoxyethoxy)-phenyl]-5,7-di-tert-butylbenzofuran-2-one,5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]-benzofuran-2-one,3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one],5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one,3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(3,4-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(2,3-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one.

The above mentioned radical generators and additives are for examplepresent in step B) in an amount of 0.01 to 1% by weight based on theweight of the total polymer.

For instance step B is carried out in the presence of 0.01 to 0.5% ofprocessing stabilizers/antioxidants.

The final comb or graft polymers are useful in many applications such ascompatibilizers in polymer blends or alloys, adhesion promoters betweentwo different substrates, surface modification agents, nucleatingagents, coupling agents between filler and polymer matrix or dispersingagents, material for shaping parts or films.

The polymers prepared by the present invention are particularly usefulfor following applications:

adhesives, detergents, dispersants, emulsifiers, surfactants, defoamers,adhesion promoters, corrosion inhibitors, viscosity improvers,lubricants, rheology modifiers, thickeners, crosslinkers, papertreatment, water treatment, electronic materials, paints, coatings,photography, ink materials, imaging materials, superabsorbants,cosmetics, hair products, preservatives, biocide materials or modifiersfor asphalt, leather, textiles, ceramics and wood.

The following examples illustrate the invention.

EXAMPLE A1 Grafting of NO-terminated Polystyrene (PS) ontoStyrene-Butadiene-Styrene (SBS) Synthesis of the macroinitiator 1:acetic acid 2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-PS(according to step A, a1)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged Schlenk tube, 1 mol % nitroxyl ether (compound 101) isdissolved in 45.45 g styrene. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 110° C. for6 hours. After polymerization, residual monomer is removed under vacuumat 70° C. and the polymer is dried at 70° C. in vacuum until constantweight is achieved. Molecular weight is determined as described below(M_(n)=4200 g/mol).

Synthesis of the macroinitiator 2: acetic acid2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-PS (according tostep A, a2)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged Schlenk tube, 1 mol % of a nitroxyl radical (compound 102)and 0.77 mol % Benzoylperoxide (BPO) as initiator are dissolved in 45.45g styrene. The solution is degassed in three consecutivefreeze-thaw-cycles and then purged with argon. The stirred solution isthen immersed in an oil bath and polymerized at 130° C. for 6 hours.After polymerization, residual monomer is removed under vacuum at 70° C.and the polymer is dried at 70° C. in vacuum until constant weight isachieved. Molecular weight is determined as described below (M_(n)=10400g/mol).

The compounds are prepared according to example 1 of GB 2 361 235.

Step B)

A mixture of 350 g SBS (Kraton D 1102 CU (Shell)) and 35 g (10%)NO-terminated-polystyrene as given in table 1 is extruded in a twinscrew extruder (Haake TW 100) at 200° C. at 50 rpm and the resultingpolymer is granulated. 10 g of the granulated polymer are dissolved intetrahydrofurane (THF), precipitated in methanol and dried at 70° C. invacuum until constant weight is achieved.

Molecular weight (step A and B) and molecular weight distribution aredetermined by size exclusion chromatography (SEC) on a HP 1090 liquidchromatograph (column PSS 1, lengths 60 cm, rate 1 ml/min, concentration10 mg polymer in 1 ml THF; software: winGPC/Polymer Standard Services(PSS), Mainz, Germany) using THF as eluent and a column combinationcalibrated with narrow polystyrene standards (Polymer Laboratories). Thepolydispersity is calculated from M_(n) (g/mol) and M_(w) (g/mol) asPD=M_(w)/M_(n). The results are shown in Table 1.

TABLE 1 Grafting of NO-terminated-PS onto SBS Increase ExampleNO-terminated PS Mn [g/mol] of Mn [%] PD reference None 65530 0 1.3 110% macroinitiator 1 72320 10.4 1.3 2 10% macroinitiator 2 78290 19.51.2 Reference: SBS extruded, 200° C., 50 rpm

EXAMPLE A2 Grafting of NO-terminated Polystyrene (PS) ontoEthylene-Propylene-Diene Modified (EPDM) Synthesis of macroinitiator 3:acetic acid 2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-PS(according to example A1, step A)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged Schlenk tube, 1 mol % nitroxyl ether (compound 101) isdissolved in 45.45 g styrene. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 130° C. for6 hours. After polymerization, residual monomer is removed under vacuumat 70° C. and the polymer is dried at 70° C. in vacuum until constantweight is achieved. Molecular weight is determined as described inExample A1 (M_(n)=7300 g/mol)

Synthesis of macroinitiator 4: Acetic acid2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-PS (according toexample A1, step A)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged Schlenk tube, 0.1 mol % nitroxyl ether (NOR) is dissolvedin 45.45 g styrene. The solution is degassed in three consecutivefreeze-thaw-cycles and then purged with argon. The stirred solution isthen immersed in an oil bath and polymerized at 130° C. for 6 hours.After polymerization, residual monomer is removed under vacuum at 70° C.and the polymer is dried at 70° C. in vacuum until constant weight isachieved. Molecular weight is determined as described in Example A1(Mn=27000 g/mol).

Synthesis of macroinitiator 5:2,2,6,6-Tetramethyl-4-propoxy-piperidine-terminated-PS (according toexample A1, step A)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged Schlenk tube, 1 mol % nitroxyl ether (compound 103) isdissolved in 45.45 g styrene. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 130° C. for6 hours. After polymerization, residual monomer is removed under vacuumat 70° C. and the polymer is dried at 70° C. in vacuum until constantweight is achieved. Molecular weight is determined as described inExample A1 (M_(n)=8000 g/mol).

The compound is prepared in analogy to the preparation described in GB 2361 235 from commercially available starting materials.

Step B)

350 g EPDM (Buna EP G 3850 (Bayer AG) is reacted together with 35 g(10%) NO-terminated-polystyrene as given in Table 2 in a kneader(Brabender W50, volume 55 cm³) at 200° C., 40 rpm and 10 min reactiontime. 10 g of the resulting polymer were dissolved in1,2-dichlorobenzene, precipitated in methanol and dried at 70° C. invacuum until constant weight is achieved. The number average molecularweight and the molecular weight distribution are determined by hightemperature gel-permeation-chromatography (HT-GPC) with a Waters 150C (5PS columns of type μ-Styragel 500 Å+HT3+HT4+HT5+HT6, temperature 140°C., rate 1 ml/min, calibration with polystyrene standard supplied fromPolymer Standard Services (PSS) using trichlorobenzene as eluent. Thepolydispersity is calculated from M_(n) (g/mol) and M_(w) (g/mol) asPD=M_(w)/M_(n).

TABLE 2 Grafting of NO-terminated-PS onto EPDM Example NO-terminated PSMn [g/mol] PD reference none 12600 17.6 1 10% macroinitiator 1 84600 2.12 10% macroinitiator 2 93980 2.2 3 10% macroinitiator 3 83300 2.4reference: EPDM after 10 min. in the kneader

EXAMPLE A3 Grafting of NO-terminated Poly-n-Butylacrylate (P-n-BuA) ontoEthylene-Propylene-Diene Modified (EPDM) Synthesis of macroinitiator 6:acetic acid 2,6-diethyl-2,3,6-trimethyl-piperidine terminated P-n-BuA(according to example A1, step A)

n-Butylacrylate is distilled under reduced pressure prior to use. In adry, argon-purged Schlenk tube, 1 mol % nitroxyl ether (compound 101) isdissolved in 55.9 g n-butylacrylate. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 110° C. for6 hours. After polymerization, residual monomer is removed under vacuumat 30° C. and the polymer is dried at 30° C. in vacuum until constantweight is achieved. Molecular weight is determined as described inExample A1 (M_(n)=5800 g/mol).

Synthesis of macroinitiator 7: acetic acid2,6-Diethyl-2,3,6-trimethyl-piperidine terminated P-n-BuA (according toexample A1, step A)

n-butylacrylate is distilled under reduced pressure prior to use. In adry, argon-purged Schlenk tube, 1 mol % nitroxyl ether (compound 101) isdissolved in 55.9 g n-butylacrylate. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 130° C. for24 hours. After polymerization, residual monomer is removed under vacuumat 30° C. and the polymer is dried at 30° C. in vacuum until constantweight is achieved. Molecular weight is determined as described inExample A1 (M_(n)=10400 g/mol).

Step B)

350 g EPDM is reacted in the presence of 35 g (10%)NO-terminated-poly-n-butylacrylate (see table 3) in a kneader (BrabenderW50, volume 55 cm³) at 200° C., 40 rpm and 10 min reaction time. 10 g ofthe resulting polymer were solved in 1,2-Dichlorobenzene, precipitatedin Methanol and dried at 70° C. in vacuum until constant weight isachieved. The number average molecular weight and the molecular weightdistribution are determined by high temperaturegel-permeation-chromatography (HT-GPC) with a Waters 150C (5 PS columnsof type μ-Styragel 500 Å+HT3+HT4+HT5+HT6, temperature 140° C., rate 1ml/min, calibration with polystyrene standard supplied from PolymerStandard Services (PSS) using trichlorobenzene as eluent. Thepolydispersity is calculated from M_(n) (g/mol) and M_(w) (g/mol) asPD=M_(w)/M_(n).

TABLE 3 Grafting of NO-term.-P-n-BuA onto EPDM Example NO-terminated PSMn [g/mol] PD reference none 12600 17.6 1 10% macroinitiator 6 64300 3.12 10% macroinitiator 7 67000 2.6 reference: EPDM after 10 min. in thekneader

EXAMPLE A4 Grafting of NO-terminated-SAN (styrene-co-acrylonitrilecopolymer) onto Styrene-Butadiene-Styrene (SBS) Synthesis of themacroinitiator 8: acetic acid2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-SAN (according toexample A1, step A)

Styrene is distilled under reduced pressure prior to use andacrylonitrile is used undistilled. In a dry, argon-purged 1 l-autoclave,1 mol % nitroxyl ether (compound 101) is dissolved in 375 g styrene and125 g acrylonitrile. The solution is degassed and purged with argon. Thestirred solution is polymerized at 110° C. for 6 hours. Afterpolymerization, residual monomer is removed under vacuum at 70° C. andthe polymer is dried at 70° C. in vacuum until constant weight isachieved. Molecular weight is determined as described in Example A1(M_(n)=3800 g/mol).

Step B)

A mixture of 350 g SBS (Kraton D 1102 CU (Shell)) and 35 g (10%)NO-terminated-SAN as given in table 4 is extruded in a twin screwextruder (Haake TW 100, vented screw) at 200° C. (220° C.) at 50 rpm andthe resulting polymer is granulated. 10 g of the granulated polymer aredissolved in tetrahydrofurane (THF), precipitated in methanol and driedat 70° C. in vacuum until constant weight is achieved.

Molecular weight and molecular weight distribution are determined bysize exclusion chromatography (SEC) on a HP 1090 liquid chromatograph(column PSS 1, lengths 60 cm, rate 1 ml/min, concentration 10 mg polymerin 1 ml THF; software: winGPC/Polymer Standard Services (PSS), Mainz,Germany) using THF as eluent and a column combination calibrated withnarrow polystyrene standards (Polymer Laboratories). The polydispersityis calculated from M_(n) (g/mol) and M_(w) (g/mol) as PD=M_(w)/M_(n).The results are shown in Table 4.

TABLE 4 Grafting of NO-terminated-SAN onto SBS Temp Mn Increase ofExample NO-terminated SAN [° C.] [g/mol] Mn [%] PD Reference 1 None 20080000 0 1.2 1 10% macroinitiator 8 200 87500 9.4 1.3 Reference 2 None220 83430 0 1.3 2 10% macroinitiator 8 220 99230 18.9 1.9 Reference 1:SBS extruded, 200° C., 50 rpm Reference 2: SBS extruded, 220° C., 50 rpm

EXAMPLE A5 Grafting of NO-terminated-SAN (styrene-co-acrylonitrilecopolymer, higher molecular weight) onto Styrene-Butadiene-Styrene (SBS)Synthesis of the macroinitiator 9: acetic acid2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-SAN (according toexample A1, step A)

Styrene is distilled under reduced pressure prior to use andacrylonitrile is used undistilled. In a dry, argon-purged 2 l-autoclave,0.1 mol % nitroxyl ether (compound 101) is dissolved in 1125 g styreneand 375 g acrylonitrile. The solution is degassed and purged with argon.The stirred solution is polymerized at 110° C. for 6 hours. Afterpolymerization, residual monomer is removed under vacuum at 70° C. andthe polymer is dried at 70° C. in vacuum until constant weight isachieved. Molecular weight is determined as described in Example A1(M_(w)=29700 g/mol).

Step B)

A mixture of 350 g SBS (Kraton D 1102 CU (Shell)) and 35 g (10%)NO-terminated-SAN as given in table 5 is extruded in a twin screwextruder (Haake TW 100, compounding screw) at 200° C. (220° C.) at 50rpm and the resulting polymer is granulated. 10 g of the granulatedpolymer are dissolved in tetrahydrofurane (THF), precipitated inmethanol and dried at 70° C. in vacuum until constant weight isachieved.

Molecular weight and molecular weight distribution are determined bysize exclusion chromatography (SEC) on a HP 1090 liquid chromatograph(column PSS 1, lengths 60 cm, rate 1 ml/min, concentration 10 mg polymerin 1 ml THF; software: winGPC/Polymer Standard Services (PSS), Mainz,Germany) using THF as eluent and a column combination calibrated withnarrow polystyrene standards (Polymer Laboratories). The polydispersityis calculated from M_(n) (g/mol) and M_(w) (g/mol) as PD=M_(w)/M_(n).The results are shown in Table 5.

TABLE 5 Grafting of NO-terminated-SAN onto SBS Temp Mw Increase ofExample NO-terminated SAN [° C.] [g/mol] Mw [%] PD Reference 1 None 20091530 0 1.2 1 10% macroinitiator 9 200 102600 12.1 1.7 Reference 2 None220 100700 0 1.2 2 10% macroinitiator 9 220 127600 26.7 1.8 Reference 1:SBS extruded, 200° C., 50 rpm Reference 2: SBS extruded, 220° C., 50 rpm

EXAMPLE A6 Grafting of NO-terminated-SAN (styrene-co-acrylonitrilecopolymer) onto Styrene-Butadiene-Styrene (SBS) Synthesis of themacroinitiator 10: acetic acid2,6-diethyl-2,3,6-trimethyl-1-piperidine-terminated-SAN (according toexample A1, step A)

Styrene is distilled under reduced pressure prior to use andacrylonitrile is used undistilled. In a dry, argon-purged 2 l-autoclave,1 mol % nitroxyl ether (compound 101) is dissolved in 1125 g styrene and375 g acrylonitrile. The solution is degassed and purged with argon. Thestirred solution is polymerized at 110° C. for 6 hours. Afterpolymerization, residual monomer is removed under vacuum at 70° C. andthe polymer is dried at 70° C. in vacuum until constant weight isachieved. Molecular weight is determined as described above (M_(n)=4270g/mol; yield 41%).

Step B)

A mixture of 350 g SBS (Kraton D 1102 CU (Shell)), 35 g (10%)NO-terminated-SAN and eventually 0.6 g (0.2%) Irganox 1520 (asprocessing stabilizer) as given in table 6 is extruded in a twin screwextruder (Haake TW 100, vented screw) at 200° C. at 50 rpm and theresulting polymer is granulated. 10 g of the granulated polymer aredissolved in tetrahydrofurane (THF), precipitated in methanol and driedat 70° C. in vacuum until constant weight is achieved.

Molecular weight and molecular weight distribution are determined bysize exclusion chromatography (SEC) on a HP 1090 liquid chromatograph(column PSS 1, lengths 60 cm, rate 1 ml/min, concentration 10 mg polymerin 1 ml THF; software: winGPC/Polymer Standard Services (PSS), Mainz,Germany) using THF as eluent and a column combination calibrated withnarrow polystyrene standards (Polymer Laboratories). The polydispersityis calculated from M_(n) (g/mol) and M_(w) (g/mol) as PD=M_(w)/M_(n).The results are shown in Table 6.

TABLE 6 Grafting of NO-terminated-SAN onto SBS Mw Increase Irganox [g/of Example NO-terminated-SAN 1520 mol] Mw [%] PD MFR Reference None94000 0 1.2 0.87 1 10% macroinitiator 100000 6.4 1.3 0.48 10 2 10%macroinitiator 0.2 100000 6.4 1.2 0.62 10 Reference: SBS extruded, 200°C., 50 rpm MFR (melt flow rate): 190° C., 1.2 kg (according to ISO 1133)Temperature for all extrusions: 200° C. (50 rpm)

Addition of an antioxidant, such as Irganox® 1520 avoids crosslinking ofthe elastomer.

1. A process for the preparation of a grafted thermoplastic orelastomeric polymer or copolymer, which process comprises in a firststep A) the preparation of a nitroxyl terminated oligomer or polymer bycontrolled free radical polymerization of an ethylenically unsaturatedmonomer or monomer mixture a1) in the presence of a nitroxyl ethercontaining a structural element of formula (Ia), wherein X is selectedsuch, that cleavage of the O—X bond occurs and a radical X• is formedcapable of initiating polymerization; or a2) in the presence of anitroxyl radical containing a structural element of formula (Ib) and afree radical initiator capable of initiating polymerization; whereunreacted monomer or monomers are removed and the nitroxyl terminatedoligomer or polymer is isolated, and in a second step B) heating, mixingand reacting the nitroxyl terminated oligomer or polymer of step A)together with a thermoplastic or elastomeric polymer or copolymer at atemperature of between 150° C. and 300° C., wherein the structuralelements of formula (Ia) and (Ib) are

wherein G₁, G₂, G₃, G₄ are independently C₁-C₆alkyl or G₁ and G₂ or G₃and G₄, or G₁ and G₂ and G₃ and G₄ together form a C₅-C₁₂cycloalkylgroup; and G₅, G₆ independently are H, C₁-C₁₈alkyl, phenyl, naphthyl ora group COOC₁-C₁₈alkyl, where X is selected from the group consisting of

R₂₀ is hydrogen or C₁-C₁₂alkyl; the alkyl groups are unsubstituted orsubstituted with one or more —OH, —COOH or —C(O)R₂₀ groups; and the arylgroups are phenyl or naphthyl which are unsubstituted or substitutedwith C₁-C₁₂alkyl, halogen, C₁-C₁₂alkoxy, C₁-C₁₂alkylcarbonyl, OH, —COOHor —COO(C₁-C₁₂)alkyl and where the thermoplastic or elastomeric polymeror copolymer is selected from the group consisting of low densitypolyethylene, high density polyethylene, polyproylene, polystyrene,styrene-block copolymers, ethylene-propylene-diene modified rubber,ethylene propylene rubber, polybutylene, polyisobutylene andpoly-4-methylpentene-1.
 2. A process according to claim 1 wherein thenitroxyl ether or the nitroxyl radical is of formula A, A′, B, B′ O orO′

wherein G₁, G₂, G₃ and G₄ are independently alkyl of 1 to 4 carbonatoms, or G₁ and G₂ together and G₃ and G₄ together, or G₁ and G₂together or G₃ and G₄ together are pentamethylene; G₅ and G₆ areindependently hydrogen or C₁-C₄ alkyl; m is 1, 2, 3 or 4 R, if m is 1,is hydrogen, C₁-C₁₈alkyl which is uninterrupted or C₂-C₁₈alkyl which isinterrupted by one or more oxygen atoms, cyanoethyl, benzoyl, glycidyl,a monovalent radical of an aliphatic carboxylic acid having 2 to 18carbon atoms, of a cycloaliphatic carboxylic acid having 7 to 15 carbonatoms, or an α,β-unsaturated carboxylic acid having 3 to 5 carbon atomsor of an aromatic carboxylic acid having 7 to 15 carbon atoms, whereeach carboxylic acid can be substituted in the aliphatic, cycloaliphaticor aromatic moiety by 1 to 3 —COOZ₁₂ groups, in which Z₁₂ is H,C₁-C₂₀alkyl, C₃-C₁₂alkenyl, C₅-C₇cycloalkyl, phenyl or benzyl; or R is amonovalent radical of a carbamic acid or phosphorus-containing acid or amonovalent silyl radical; R, if m is 2, is C₂-C₁₂alkylene,C₄-C₁₂alkenylene, xylylene, a divalent radical of an aliphaticdicarboxylic acid having 2 to 36 carbon atoms, or a cycloaliphatic oraromatic dicarboxylic acid having 8-14 carbon atoms or of an aliphatic,cycloaliphatic or aromatic dicarbamic acid having 8-14 carbon atoms,where each dicarboxylic acid may be substituted in the aliphatic,cycloaliphatic or aromatic moiety by one or two —COOZ₁₂ groups; or R isa divalent radical of a phosphorus-containing acid or a divalent silylradical; R, if m is 3, is a trivalent radical of an aliphatic,cycloaliphatic or aromatic tricarboxylic acid, which may be substitutedin the aliphatic, cycloaliphatic or aromatic moiety by —COOZ₁₂, of anaromatic tricarbamic acid or of a phosphorus-containing acid, or is atrivalent silyl radical, R, if m is 4, is a tetravalent radical of analiphatic, cycloaliphatic or aromatic tetracarboxylic acid; p is 1, 2 or3, R₁ is C₁-C₁₂alkyl, C₅-C₇cycloalkyl, C₇-C₈aralkyl, C₂-C₁₈alkanoyl,C₃-C₅alkenoyl or benzoyl; when p is 1, R₂ is C₁-C₁₈alkyl,C₅-C₇cycloalkyl, C₂-C₈alkenyl unsubstituted or substituted by a cyano,carbonyl or carbamide group, or is glycidyl, a group of the formula—CH₂CH(OH)—Z or of the formula —CO—Z— or —CONH—Z wherein Z is hydrogen,methyl or phenyl; or when p is 2, R₂ is C₂-C₁₂alkylene, C₆-C₁₂-arylene,xylylene, a —CH₂CH(OH)CH₂—O—B—O—CH₂CH(OH)CH₂— group, wherein B isC₂-C₁₀alkylene, C₆-C₁₅arylene or C₆-C₁₂cycloalkylene; or, provided thatR₁ is not alkanoyl, alkenoyl or benzoyl, R₂ can also be a divalent acylradical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid ordicarbamic acid, or can be the group —CO—; or R₁ and R₂ together when pis 1 can be the cyclic acyl radical of an aliphatic or aromatic 1,2- or1,3-dicarboxylic acid; or R₂ is a group

where T₇ and T₈ are independently hydrogen, alkyl of 1 to 18 carbonatoms, or T₇ and T₈ together are alkylene of 4 to 6 carbon atoms or3-oxapentamethylene; when p is 3, R₂ is 2,4,6-triazinyl; and X isselected from the group consisting of

R₂₀ is hydrogen or C₁-C₁₂alkyl; the alkyl groups are unsubstituted orsubstituted with one or more —OH, —COOH or —C(O)R₂₀ groups; and the arylgroups are phenyl or naphthyl which are unsubstituted or substitutedwith C₁-C₁₂alkyl, halogen, C₁-C₁₂alkoxy, C₁-C₁₂alkylcarbonyl, OH, —COOHor —COO(C₁-C₁₂)alkyl.
 3. A process according to claim 2 wherein thenitroxyl ether or the nitroxyl radical is of formula A, A′, B, B′, O orO′

wherein m is 1, R is hydrogen, C₁-C₁₈alkyl which is uninterrupted orinterrupted by one or more oxygen atoms, cyanoethyl, benzoyl, glycidyl,a monovalent radical of an aliphatic carboxylic acid having 2 to 18carbon atoms, of a cycloaliphatic carboxylic acid having 7 to 15 carbonatoms, or an α,β-unsaturated carboxylic acid having 3 to 5 carbon atomsor of an aromatic carboxylic acid having 7 to 15 carbon atoms; p is 1;R₁₀₁ is C₁-C₁₂alkyl, C₅-C₇cycloalkyl, C₇-C₈aralkyl, C₂-C₁₈alkanoyl,C₃-C₅alkenoyl or benzoyl; R₁₀₂ is C₁-C₁₈alkyl, C₅-C₇cycloalkyl,C₂-C₈alkenyl unsubstituted or substituted by a cyano, carbonyl orcarbamide group, or is glycidyl, a group of the formula —CH₂CH(OH)—Z orof the formula —CO—Z or —CONH—Z wherein Z is hydrogen, methyl or phenyl;G₆ is hydrogen and G₅ is hydrogen or C₁-C₄alkyl, G₁, G₂, G₃ and G₄ aremethyl; or G₁ and G₃ are methyl and G₂ and G₄ are ethyl or propyl or G₁and G₂ are methyl and G₃ and G₄ are ethyl or propyl; and X is selectedfrom the group consisting of —CH₂-phenyl, CH₃CH-phenyl, (CH₃)₂C-phenyl,(C₅-C₆cycloalkyl)₂CCN, (CH₃)₂CCN, —CH₂CH═CH₂, CH₃CH—CH═CH₂(C₁-C₄alkyl)CR₂₀—C(O)-phenyl, (C₁-C₄)alkyl-CR₂₀—C(O)—(C₁-C₄)alkoxy,(C₁-C₄alkyl-CR₂₀—C(O)—(C₁-C₄alkyl,(C₁-C₄alkyl-CR₂₀—C(O)—N-di(C₁-C₄alkyl,(C₁-C₄alkyl-CR₂₀—C(O)—NH(C₁-C₄)alkyl and (C₁-C₄)alkyl-CR₂₀—C(O)—NH₂,wherein R₂₀ is hydrogen or (C₁-C₄)alkyl.
 4. A process according to claim2 wherein G₂ and G₄ are ethyl, G₁ and G₃ are methyl, G₆ is hydrogen andG₅ is methyl.
 5. A process according to claim 1 wherein the free radicalinitiator of component a2) is a bis-azo compound, a peroxide, a peresteror a hydroperoxide.
 6. A process according to claim 1, wherein thenitroxylether of component a1) or the nitroxyl radical of component a2)is present in an amount of from 0.001 mol-% to 20 mol-%, based on themonomer or monomer mixture.
 7. A process according to claim 1, whereinthe free radical initiator is present in an amount of from 0.001 mol-%to 20 mol-%, based on the monomer or monomer mixture.
 8. A processaccording to claim 1, wherein the ethylenically unsaturated monomer isselected from the group consisting of styrene, substituted styrene,conjugated dienes, vinyl acetate, vinylpyrrolidone, vinylimidazole,maleic anhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acidsalts, (alkyl)acrylic esters, (meth)acrylonitriles, (alkyl)acrylamides,vinyl halides and vinylidene halides.
 9. A process according to claim 7,wherein the ethylenically unsaturated monomer is a compound of formulaCH₂═C(R_(a))—(C═Z)—R_(b), wherein R_(a) is hydrogen or C₁-C₄alkyl, R_(b)is NH₂, O⁻(Me⁺), glycidyl, unsubstituted C₁-C₁₈alkoxy, C₂-C₁₀₀alkoxyinterrupted by at least one N and/or O atom, or hydroxy-substitutedC₁-C₁₈alkoxy, unsubstituted C₁-C₁₈alkylamino, di(C₁-C₁₈alkyl)amino,hydroxy-substituted C₁-C₁₈alkylamino or hydroxy-substituteddi(C₁-C₁₈alkyl)amino, —O—CH₂—CH₂—N(CH₃)₂ or —O—CH₂—CH₂—N⁺H(CH₃)₂An⁻; An⁻is a anion of a monovalent organic or inorganic acid; Me is a monovalentmetal atom or the ammonium ion and Z is oxygen or sulfur.
 10. A processaccording to claim 1 wherein step B) is performed in an extruder, mixeror kneading apparatus.
 11. A process according to claim 1 wherein instep B) additionally a processing stabilizer and/or antioxidant isadded.
 12. A process according to claim 1 wherein in step B)additionally a radical generator is added.
 13. A process according toclaim 1 wherein the nitroxyl terminated polymer or oligomer of step A)has a number average molecular weight of from 1000 to 100 000 Dalton.14. A process according to claim 1 wherein the nitroxyl terminatedpolymer or oligomer of step A) has a polydispersity (PD) from 1.0 to2.0.
 15. A process according to claim 1 wherein the nitroxyl terminatedpolymer or oligomer of step A) is added to the thermoplastic orelastomeric polymer or copolymer in an amount from 0.1% to 50% by weightbased on the weight of the thermoplastic or elastomeric polymer orcopolymer.